Rotary multi-compartment distillation drum having radially adjustable outlet to varythickness of liquid layer



Aug. 6, 1968 E. BECHARD 3,396,088

ROTARY MULTI-GOMPARTMENT DISTILLATION'DRUM HAVING RADIALLY ADJUSTABLEOUTLET T0 VARY THICKNESS 0F LIQUID LAYER Filed April 1, 1964 I 5Sheets-Sheet 1 OVERF UW FIG, 1

mvmrol? 1 il'mzle Bedlam] 5 dizfys 6, 1968 E. BECHARD 3,396,088

ROTARY MULTI-COMPARTMENT DISTILLATION DRUM HAVING RADIALLY ADJUSTABLEOUTLET TO VARY THICKNESS 0F LIQUID LAYER Filed April 1, 1964 5Sheets-Sheet 2 6, 1968 E. BECHARD 3,396,088

ROTARY MULTI-COMPARTMENT DISTILLATION DRUM HAVING RADIALLY ADJUSTABLEOUTLET T0 VARY TKICKNESS OF LIQUID LAYER Filed April 1, 1964 5Sheets-Sheet 5 Aug 1953 E. BECHARD 3,396,083

ROTARY MULTI-COMPARTMENT DISTIL-LATICN DRUM HAVING RADIALLY ADJUSTABLEOUTLET T0 VARY THICKNESS 0F LIQUID LAYER 5 Sheets-Sheet 4 Filed April 1,1964 Aug. 6, 1968 E. BECHARD 3,395,088

ROTARY MULTI-CQMPARTMENT DISTILLATION DRUM HAVING RADIALLY ADJUSTABLEOUTLET TO VARY THICKNESS OF LIQUID LAYER Filed April 1, 1964 5Sheets-Sheet 5 United States Patent 3,396,088 ROTARY MULTI-COMPARTMENTDISTILLATION DRUM HAVING RADIALLY ADJUSTABLE OUT- LET T0 VARY THICKNESS0F LIQUID LAYER Emile Bechard, Paris, France, assignor of fifty percentto Rene G. LeVaux Filed Apr. 1, 1964, Ser. No. 356,434 4 Claims. (Cl.202238) This invention relates to the treatment of water in suchprocesses as concentration, distillation, condensation andrefrigeration, and it relates more particularly to methods and equipmentfor use in the practice of same.

Whether it is a question of heat exchangers or distillation apparatus,such equipment is usually very large, heavy and cumbersome. In themajority of cases, distillation apparatus requires heating, as by steammade available from a boiler.

If the efficiency of each machine is considered, the total efficiency ispoor. For example, an efficiency of 0.70 at the boiler and 0.80 at theconcentrator, would give a total efficiency of 0.7 0.8, or 0.56.

In accordance with the present invention, all of the elements aregrouped as one whereby a higher efiiciency can be achieved. The use ofcentrifugal force to enhance heat transfer allows for considerableoutput per unit surface area.

The aggregate of these elements allows for the satisfaction of thevarious requirements with a minimum amount of floor space and with costsreduced to a minimum insofar as investments and exploitation areconcerned.

It is an object of this invention to provide an improved method andmeans for carrying out such water treatment processes and to providemore eflicient and better equipment and method for effecting the same.

These and other objects and advantages of this invention willhereinafter appear, and for purposes of illustration, but not oflimitation, an embodiment of the invention is shown in the accompanyingdrawings, in which FIG. 1 is a schematic sectional view taken crosswisethrough the center of apparatus embodying features of this inventionshowing the operating principles of a centrifugal concentrator, aregulator and control for the filling operation;

FIG. 2 is a schematic sectional view of a portion of the apparatus usedfor large volumes of liquid and vapor, as needed when substantialsupplies thereof are alternately required;

FIG. 3 is a schematic sectional view showing a lamellar exchangeradapted to be heated or cooled by an auxiliary li uid;

FIG. 4 is a schematic sectional view of a portion of the equipment shownin FIG. 1 but in which the annular body is replaced by a group of pipes;

FIG. 5 is a sectional view taken crosswise through a half section of theapparatus shown in FIG. 4;

FIG. 6 is a schematic sectional view showing a heat exchanger with aspiral group of pipes positioned adjacent the inner surface of theapparatus and immersed in the liquid;

FIG. 7 is a sectional elevational view similar to that of FIG. 6 butshowing a modification thereof with spiral pipes mounted tangential tothe liquid to be heated or cooled;

FIG. 8 is a schematic sectional view of an exchanger in which one of thefluids is a vapor, air or gas adapted to circulate freely on thesurfaces of the liquid to be heated, cooled or evaporated;

FIG. 9 is a schematic sectional view showing the use 3,396,088 PatentedAug. 6, 1968 of a syphon or ladle to extract the treated or surplusliquids while in motion;

FIG. 10 is a schematic sectional view which, in the upper portion, showsthe principle of an exchanger with a padding or thermal insulation toexclude the risks of localized heat, especially in concentrating viscousmaterials which are sensitive to temperature variations and which, inthe lower portion, shows a conical bowl containing a reverse of materialto be treated; and

FIG. 11 is a schematic sectional view showing an embodiment of theinvention in methodic circulation of the heating and cooling gases andthe circulation of the liquids to be heated, vaporized or cooled.

These figures are not restrictive, especially not as to dimensions, andin certain cases they may be combined. For example, one device willproduce a fluid, another will use it and a third will make an inversethermal exchange, by condensing a vapor or by cooling a liquid.

In the same way, all materials, metals or compatible substances, withthe pressures, temperatures, the aggressivity of the products or themechanical resistances, may be used.

Finally, the communicating gear may be any of the known methods,mechanical, thermal or electrical, by belts, chains or grooved pulleys.

Description To obtain the centrifugal force used to accelerate thethermal exchanges or to localize them, all these embodiments revolveabout an axis A-A, supported by ball or roller bearings, or pads 1.

They are activated by pulleys 2 mounted on the central shafts 3 for thesingle rotation machines, and by pulleys 4 mounted on the encased shafts5 for the machines having two concentric rotational elements.

All these machines include a bowl, drum or rotor, generally designated6, and which comprise a rotatable sleeve 3 or 5 depending on the processto be used.

This principal element 6 is often supplemented by the annular chamber 7on the intake side for the product to be treated and a chamber 8 on theoutlet side for the products of liquids that have been treated.

The drum or rotor 6, as illustrated in FIG. 1, comprises annularchambers 7 and 8, as provided by the discs 9 for integration with thedriving shaft. These discs are drilled with holes 10 for thecommunication between these elements. In certain cases, the discs arereplaced by arms 11 as shown in FIG. 6.

The arrival of the liquids to be treated is effected by a pipe 12 whenthe feed is natural, without pressure. Instead the liquid can be fedthrough a drilling 13 in the shaft 3 and by the interposition of astuffing box for the feed of liquids under pressure. These drillingscommunicate with the intake chamber or thermal exchange chambers by theorifices 14.

In installations containing one or more coils 15, these drillings on theshaft communicate with the one or more coils. When such coils are notapplied to the inner wall of the bowl, they are supported by squirrelcage bars 16.

The extraction of the heated, cooled, or concentrated liquid is made bythe syphons or ladies 17 fixed or adjustable by screws and steeringwheels 17a when under pressure 18, or by the drillings 19 and theinterposition of the stuffing box for an outlet under pressure. If thereis a need to produce a vapor at a pressure higher than that of theatmosphere, it may be received in a casing 20, and its outlet may befacilitated by extractor pipes 21, then directed to other utilizationsor treatments by the pipe 22.

In the exchangers with large volumes of liquids and vapor, so as not todisturb the exchanges in course, the

liquid to be treated is admitted in a circular sheet, formed by theinterposition of. a disc 23.

In the embodiments with groups of pipes parallel to the axis, or spiral,these pipes 24 are encased, expanded or set onto the plate 9. In theseembodiments, the flames or heated gases pass across the group of pipes,thus increasing the exchange surfaces.

In the lamellar embodiments, the arrangement includes an intermediatedrum 25 forming a circular space 26 With 6, in which the heating orcooling liquid circulates. The surplus inside volume is filled by a drum27 leaving between 25 a sheet of liquid 28 which will rapidly circulate,in any case with the least inertia that could come from a large volume.

The submerged pipes 15 tangential to the drum 6 allow the instantaneousheating of all the volume in the course of treatment, on the other hand,in the arrangements with the pipes tangential to the liquid, supportedby the bars 16, only the inside surface of the top of the liquid isheated, thus bringing no thermal modification to the mass of the liquidin the course of treatment.

In the equipments that use a vapor, a gas or air, these elements, afterhaving fulfilled their functions, being saturated, are extracted by anaspirating device 29.

To create a thermal padding so as to avoid all local thermal charges,temperature excesses, etc., the liquid ring is contained between thebowl 6 and the bowl 30 on the inside at 6 and between the two ispredetermined quantity of liquid of easy evaporation, water for example,which will produce a vapor 32.

For semi-liquid or viscous products, the inlet will be effected by afunnel 33. They will be regularly advanced by a screw 34 which will leadthem into the treating chamber 35. In this chamber a, screw 36 revolvesslowly which advances the products in proportion as the liquid that theycontained is vaporized, extracted by 29, whereas the products areextracted by 37.

To achieve rigorously methodic thermal exchange, that is to say, countercurrent, in which the heated fluid circulates in the opposite directionto the cold fluid, so as to maintain constant the maximum divergencebetween them, on the collector, rotor, bowl or drum, pipes are mounted,called hairpin pipes 38.

The arm on the inlet side of the liquid does not pass beyond theinterior of the thickness of the collector 6. The other arm, that On theoutlet side of the heated fluid, on the other hand, continues through tothe interior of the liquid layer 39. The heated liquid or formed vaporwill escape by means of the passages 19, to be directed to its use,passing through the fixed piping by means of a conventional stuffingbox.

As far as the flames or the heated gas are concerned, which are admittedat 40, they go through to the revolving chamber 41, which revolves withthe rotor 6 and the pipes 38 avoids whirls. Thus the gasses circulatefreely to leave at 42, aspirated by the ventilator 32.

This invention can use all known types of heating, solid (wood or coal)in a fire set under the bowl, rotor or drum, by gas or liquid fuels 43from which the flames are directly projected onto the revolvingsections, which run no risk of burning, on account of the continualmovement in front of the flame.

To retain the hot gases around the exchange elements, the latter isenclosed in a casing or housing 44.

In the cases when electrical heating is being used, the electricalresistance 45 is submerged in the liquid to be heated, or supported bythe squirrel cage bars when the heating should be made on the insidelayer of the liquid 46.

If heating by infra-red rays is used, the lamps 47 are mounted insegments or rings around the elements to be heated, which revolves inthe center.

The residual heating gases, the saturated air or vapors are ejected intothe open air through the chimney 48.

When it is a question of recuperating distillation gases and eventuallycondensing them, they leave by the tube 49 which can be connected to anapparatus in vacuo or a condenser.

The ribs with their developed surfaces, have the advantage, under anequal volume, of being able to increase the exchange surfaces betweenthe metal and the gases or liquids.

The ribs parallel to the axis, or in appropriately oriented spirals,have the advantage of being able to facilitate a progessive advance inthe direction of the methodic exchanges; the radial ribs, on the otherhand, circular in shape, on the inside or the outside, would stabilizebetween each circle, forming as many circular rings, which in certaincases would be deterimental to the circulation of the liquids or gases,but which in other cases allows a selection of the produced vapor.

In nearly all these embodiments having the same aim, to concentrate, todistill, to condense or to cool, the most important part is inmaintaining a constant level in the bowl, rotor or drum while assuringthe distribution of the evaporated liquids, that is to say, assuring asupply as a function of the liquid given off in the form of vapors.

Operation It is known and has been demonstrated that the density of aliquid, vapor or gas, varies with the temperature because of theincrease or dilation of a given weight, or because of its contraction orreduction in volume.

If D is equal to the density of a liquid at rest, water for instance at10 C. or D equals 0.99907, and d the density at 1l0 C=0.951, the densityhas diminished from D to d0.99907 to 0.951=0.4807.

If water at 10 C. is placed in a rotor with a diameter of 0.5 meter,turning at 1,000 revolutions per minute, it will be subject to anacceleration of which the vapor B is given by the simplified formulathat is 56, thus a weight of one kilogram on balance will effect a pullof 56 kilograms at its center of gravity, if it turns at a speed of 1000revolutions per minute, on a radius of 0.50 meter, that is at a distanceof 0.5 meter from the axis.

By applying this coefficient 56 to the differences in density, theysuccessively become 0.99907X56=55.94792, and 0.951 56 53.256, that is adifference of It is easily understood and admitted, and experience hasshown it to be so, that with a difference of centrifugal density of2.69192, the water will separate itself in function of its density, thehottest at the center, and the coldest at the inside circumference ofthe rotor, bowl or drum.

If he heat does not act on the bowl, rotor or drum, the liquid has norelative radial movement between the inside layer and the inside of thecasing.

If, on the other hand, the casing 6 is heated, whatever the source ofheat, the water for example that is in contact with the outside casingwill become lighter proportionally to the heat received, its densitywill diminish; this diminution multiplied by the coeflicient B56 in theabove example will cause such a lightening that it will come rapidlynearer to the center, giving place to colder water, whence anaccelerated convection. This accelerated convection allows the obtainingof very considerable thermal exchanges per surface unit.

Another phenomenon improves the production, the suppression of the film,called the contact which disturbs the exchanges, the liquids being badconductors.

In the present invention the elements 6, 7 and 8 form an aggregate ofthree compartments revolving together, separated by the partitions 9 butcommunicating between themselves by the orifices 10 placed as near aspossible to the outside.

The water taken into 12 will be distributed in the rim (crown) if theaggregate revolves until the level is limited by the syphon or ladle 17.From that moment the level will be stable, regulated by the shoe 52 andthe surplus extracted by 17.

As long as the heating does not intervene, there will be no change ofmovement in the liquid.

The lighting of the burner 43 will cause a rise in temperature of thewater contained in the central body 6. The rise in temperature willcause a formation of vapor, which before escaping at 19 will betransformed by an elevation of pressure in the body 6; this pressurewill be balanced by the centrifugal force, acting on the water containedin the bodies 7 and 8, which stay at atmospheric pressure.

The pressure of the vapor will cause a difference of level H incentrifugal value, that is under pressure B H R d, this being per squarecentimeter, the center of gravity of this column being H a, the distanceR being the radius of rotation of this liquid column, the density beingexpressed in kilograms per cubic centimeter.

This contribution of heat which will make the liquid lighter on contactwith the heated wall, will force it closer to the center with a speedincreased by the acceleration B, a colder liquid Will take its place,whence the accelerated convection.

The effects of centrifugal force on the thermal exchanges may bestrictly and rigorously controlled locally by the use of pipes orconcentric drums 60, 25, 27, which bring liquids to differenttemperatures causing the exchanges.

The terminal compartments 7 and 8 being in relation with the atmosphericpressure, this type of exchanger is strictly explosion-proof. In fact asudden or abnormal excess of pressure in compartment 6 will force theliquids from compartments 7 and 8, thanks to the free passages 10.

In the case of the slowing down of the speed of rotation, thecentrifugal force diminishes and at the same time so does the pressurein compartment 6.

In the case of the machine stopping, at least half of the passages 10are immediately in contact with the atmosphere.

In the case of stoppage of the supply of the liquid to be heated orevaporated, the pressure diminishes at the same time as the thickness ofthe liquid rim (crown) to be eliminated when the passages 10 are opened.

Heating without a liquid presents no danger on account of the rotationwhich assures distribution by avoiding burnouts When the principle isused to concentrate, to distill or to dry liquids containing solidelements, that may be centifuged, it is necessary to remove and toextract these elements before they can form a layer or crust struck tothe inside of the bowl 6, isolating and risking burnouts; this removalis assured by the screws 34 and 35, to be evacuated, concentrated ordried by the centrifugal extractor 37 when the evaporated liquid isextracted by the ventilator 29.

For products that are fragile and sensitive to heat, the liquid padding31 is used, whose vapor 32 heats the cylinder 30.

As the vapor 32 cools, giving up its heat, it becomes heavier, evencondenses and returns to a liquid state 31, thus forming a cycle havinga great regularity, hence the slight temperature variations.

It will be understood that changes may be made in the details ofconstruction, arrangement and operation without departing from thespirit of the invention, especially as defined in the following claims.

I claim:

1. A device for the treatment of a liquid comprising a drum mounted forrotational movement about a horizontal axis, means for rapidly rotatingthe drum about its axis at a rate sutficient to generate centrifugalforce greater than that of gravity, a pair of axially spaced radiallyextending partitioning members secured for rotation with said drum andsubdividing the drum into a central compartment and outer compartmentson each side of the central compartment and openings in the partitioningmembers adjacent the peripheral surfaces of the drum whereby the centralcompartment communicates with each of the outer compartments, astationary inlet extending into one of the outer compartments forintroduction of liquid to be treated, a stationary outlet extending intothe other of the outer compartments with means for radial adjustment ofthe outlet for adjusting the thickness of the layer of liquid retainedon the peripheral surfaces of the compartments during rotationalmovement of the drum, vapor outlet conduit means in communication withthe interior of the central compartment inwardly of the liquid levelduring rotational movement of the drum and extending axially within thecompartments for drawing off vapors given off by the liquid in the drum,and means for heating the peripheral surface of the central compartmentwhereby, during rotational movement of the drum, the layer of the liquidon the peripheral surface of the drum having a thickness at least asgreat as the radial height of the openings communicating the drums willseparate in response to gravity with the heavier and colder liquidadjacent the outer peripheral surfaces of the drum and the lighter andhotter liquid at the interior surfaces of the liquid layer for releaseof vapors at the interior of the drum to be taken off through saidoutlet means.

2. A device as claimed in claim 1 in which the vapor outlet meanscomprises a hollow axial shaft, openings in the shaft communicating theinterior of the drum with the interior of the shaft and meanscommunicating with an end portion of the shaft beyond the drum forremoval of vapors from the shaft.

3. A device as claimed in claim 1 which includes a stationary casingenclosing the drum for the circulation of heat exchange gases and fluidstherethrough in heat exchange relationship with the periphery of thedrum.

4. A device as claimed in claim 1 which includes battles in the form ofdisc members axially spaced apart within the central compartment,alternating disc members being dimensioned to have a radius greater thanthe others with the disc members of larger radius extending into thewall of liquid with the disc members of shorter radius terminating shortof the wall of liquid, and openings in the disc members of larger radiusshort of the wall of liquid whereby vapor directed axially through theinterior of the drum passes therethrough in a sinuous path about theends of the smaller disc members and through the openings in the largerdisc members.

References Cited UNITED STATES PATENTS 2,220,171 11/1940 Noaillon 2022382,493,220 1/1950 Bibby 202-236 2,894,879 7/1959 Hickman 202 236 X2,999,796 9/1961 Bromley 202-236 3,136,707 6/ 1964 Hickman 202-2363,163,587 12/1964 Champeo 202236 X 3,200,051 8/1965 Silvern 2022361,501,515 7/1924 Testrup 202-236 X 1,748,178 2/1930 Hume 15911 X1,795,495 3/1931 Lavett 159-11 X FOREIGN PATENTS 940,896 12/ 1948France.

72,838 7/ 1953 Netherlands.

NORMAN YUDKOFF, Primary Examiner.

F. E. DRUMMOND, Assistant Examiner.

1. A DEVICE FOR THE TREATMENT OF A LIQUID COMPRISING A DRUM MOUNTED FORROTATIONAL MOVEMENT ABOUT A HORIZONTAL AXIS, MEANS FOR RAPIDLY ROTATINGTHE DRUM ABOUT ITS AXIS AT A RATE SUFFICIENT TO GENERATE CENTRIFUGALFORCE GREATER THAN THAT OF GRAVITY, A PAIR OF AXIALLY SPACED RADIALLYEXTENDING PARTITIONING MEMBERS SECURED FOR ROTATION WITH SAID DRUM ANDSUBDIVIDING THE DRUM INTO A CENTRAL COMPARTMENT AND OUTER COMPARTMENTSON EACH SIDE OF THE CENTRAL COMPARTMENT AND OPENINGS IN THE PARTITIONINGMEMBERS ADJACENT THE PERIPHERAL SURFACES OF THE DRUM WHEREBY THE CENTRALCOMPARTMENT COMMUNICATES WITH EACH OF THE OUTER COMPARTMENTS, ASTATIONARY INLET EXTENDING INTO ONE OF THE OUTER COMPARTMENTS FORINTRODUCTION OF LIQUID TO BE TREATED, A STATINARY OUTLET EXTENDING INTOTHE OTHER OF THE OUTER COMPARTMENTS WITH MEANS FOR RADIAL ADJUSTMENT OFTHE OUTLET FOR ADJUSTING THE THICKNESS OF THE LAYER OF LIQUID RETAINEDON THE PERIPHERAL SURFACES ON THE COMPARTMENTS DURING ROTATIONALMOVEMENT OF THE DRUM, VAPOR OUTLET CONDUIT MEANS IN COMMUNICATION WITHTHE INTERIOR OF THE CENTRAL COMPARTMENT INWARDLY OF THE LIQUID LEVELDRUING ROTATIONAL MOVEMENT OF THE DRUM AND EXTENDING AXIALLY WITHIN THECOMPARTMENTS FOR DRAWING OFF VAPORS GIVEN OFF BY THE LIQUID IN THE DRUM,AND MEANS FOR HEATING THE PERIPHERAL SURFACE OF THE CENTRAL COMPARTMENTWHEREBY, DURING ROTATIONAL MOVEMENT OF THE DRUM, THE LAYER OF THE LIQUIDON THE PERIPHERAL SURFACE OF THE DRUM HAVING A THICKNESS AT LEAST ASGREAT AS THE RADIAL HEIGHT OF THE OPENINGS COMMUNICATING THE DRUMS WILLSEPARATE IN RESPONSE TO GRAVITY WITH THE HEAVIER AND COLDER LIQUIDADJACENT THE OUTER PERIPHERAL SURFACES OF THE DRUM AND THE LIGHTER ANDHOTTER LIQUID AT THE INTERIOR SURFACES OF THE LIQUID LAYER FOR RELEASEOF VAPORS AT THE INTERIOR OF THE DRUM TO BE TAKEN OFF THROUGH SAIDOUTLET MENAS.